In existing avian radar systems static 3D zones can be defined as alarm zones. Within that zone specific birds (e.g. large birds and flocks) generate an audio or visual alarm to warn air traffic control. This alarm can be used to e.g. scare away birds. The alarms are based on size and location of the bird only. In practice this leads to situations where there may be too many alarms, too many false alarms or alarms that come too late.